Plane type heat exchanger

ABSTRACT

The present invention relates to a plane type heat exchanger that has a simple structure and can be easily manufactured by substituting a rectangular plane type for a spiral cylindrical type of the structure of a heat exchange pipe according to the related art which is used for a heat exchanger using combustion gas that is heated by a burner and makes laminar flow. According to the present invention, the plane type heat exchanger having heat exchange pipes, through which heating water flows, and makes heat exchange by contacting with laminar-flow combustion gas, the plane type heat exchanger, includes: a plurality of heat exchange pipes that have a rectangular cross section with a larger width of a side, which contacts with the combustion gas, than the height, and are arranged at regular intervals in parallel with each other; inner plates where both ends of the heat exchange pipes are inserted to be fixed at regular intervals; and outer plates that are communicated with the heat exchange pipes through the inner plates and form spaces covering the outer surfaces of the inner plates.

TECHNICAL FIELD

The present invention relates to a plane type heat exchanger, more particularly a plane type heat exchanger that has a simple structure and can be easily manufactured by substituting a rectangular plane type for a spiral cylindrical type of the structure of a heat exchange pipe according to the related art which is used for a heat exchanger using combustion gas that is heated by a burner and makes laminar flow.

BACKGROUND ART

In general, a pin and tube type that transfers combustion heat of combustion gas to fluid flowing inside a heat exchange pipe through heat transfer pins provided around the surface of the heat exchange pipe is used for heat exchangers that are used in hot-water and heating boilers that use fossil fuels.

Devices for making turbulent flow are designed for the pin and tube type heat exchangers to improve heat exchange performance and the heat transfer pins are provided, such that heat exchange efficiency is improved. However, numerous heat transfer pins are provided, thereby increasing cost.

In consideration of the problem in relation to cost, a laminar flow type heat exchanger, a tube type heat exchanger without heat transfer pins on the surface of a heat exchange pipe, which uses laminar flow of combustion gas has been designed.

It has been generally known that laminar flow type heat exchangers are low in heat transfer efficiency as compared with turbulent flow type heat exchangers; however, the laminar flow type heat exchangers can achieve high heat transfer efficiency even though heat transfer pins are not provided on the surface of a heat exchange pipe until a boundary layer where the flow of combustion gas changes from laminar flow to turbulent flow is formed.

FIG. 1 is a perspective view of a cylindrical heat exchange pipe that is used in a heat exchanger using laminar flow in the related art and FIG. 2 is a side view of the cylindrical heat exchange pipe shown in FIG. 1.

A cylindrical heat exchange pipe 10 is a spiral pipe having a flat cross section.

Low-temperature heating water flows into a heating water inlet 11 formed at one end of the cylindrical heat exchange pipe 10, and combustion heat of combustion gas that is heated by a burner (not shown) is transferred to the heating water flowing through the heat exchange pipe 10 wound spirally, such that high-temperature heating water is discharged through a heating water outlet 12 formed at the other end, for heating or hot water.

The combustion gas heated by the burner radially flows through a space formed inside the spiral cylindrical heat exchange pipe 10.

In order to increase heat transfer efficiency of the laminar flow type heat exchanger, it is important to maintain uniform gaps between the heat exchange pipes formed flat. Accordingly, as shown in FIG. 2, protruding beads 15 are formed on the flat surfaces of the cylindrical heat exchange pipe 10, such that the gaps between the pipes are maintained at the protruding distance of the beads 15 when the pipe is spirally wound and pressed.

However, the cylindrical heat exchanger in the related art is large in volume and should be spirally manufactured with the space inside the heat exchange pipe 10 uniformly maintained, such that it has a structural limit in that manufacturing is difficult and only a cylindrical burner can be used, not a plane type burner.

Further, distortion is generated at the flat portions while the cylindrical heat exchange pipe 10 is spirally manufactured, such that it is difficult to flat the surface.

DISCLOSURE OF INVENTION Technical Problem

In order to overcome the above problems, it is an object of the present invention to provide a plane type heat exchanger that makes it possible to easily manufacture heat exchange pipes, which are used in a heat exchanger using laminar flow, maintain regular gaps of spaces between the heat exchange pipes, and improve efficiency of heat transfer to heating water inside the heat exchange pipes.

Technical Solution

In order to achieve the object of the present invention, a plane type heat exchanger having heat exchange pipes, through which heating water flows, and makes heat exchange by contacting with laminar-flow combustion gas, the plane type heat exchanger, includes: a plurality of heat exchange pipes that have a rectangular cross section with a larger width of a side, which contacts with the combustion gas, than the height, and are arranged at regular intervals in parallel with each other; inner plates where both ends of the heat exchange pipes are inserted to be fixed at regular intervals; and outer plates that are communicated with the heat exchange pipes through the inner plates and form spaces covering the outer surfaces of the inner plates.

Insertion holes having sizes close to the cross-sectional area of the heat exchange pipes are formed, at positions corresponding to the heat exchange pipes, through the inner plates and both ends of the heat exchange pipes are inserted in the insertion holes.

A sub-plate is provided between the inner plate and the outer plate.

Flow channel holes having sizes smaller than the cross section of the heat exchange pipes are formed through the sub-plate.

Both ends of the heat exchange pipes are in close contact with the sub-plates.

Brazing is applied to between the inner plate and the sub-plate, the heat exchange pipe and the inner plate, and the heat exchange pipe and the sub-plate.

Brazing is applied to portions where both ends of the heat exchange pipe is inserted in the inner plate.

The outer plate is divided into a plurality of sections.

ADVANTAGEOUS EFFECTS

According to a plane type heat exchanger of the present invention it is easy to flat contact surfaces between heat exchange pipes and combustion gas by manufacturing heat exchange pipes, which are used in the heat exchanger, in a plane multi-layered structure, and it is possible to improve heat transfer efficiency by maintaining regular gaps between the heat exchange pipes.

Further, according to the present invention, it is possible to reduce the entire volume of the heat exchanger by simplifying the structure of the heat exchanger, and decrease the manufacturing cost of the heat exchanger by making it possible to use a plane type burner for the heat exchanger.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a cylindrical heat exchange pipe that is used in a heat exchanger using laminar flow in the related art.

FIG. 2 is a side view of the cylindrical heat exchange pipe shown in FIG. 1.

FIG. 3 is a cross-sectional plan view showing the structure of a plane type heat exchanger according to an embodiment of the present invention.

FIG. 4 is an exploded perspective view of FIG. 3.

FIG. 5 is a cross-sectional plan view showing the structure of a plane type heat exchanger according to another embodiment of the present invention.

FIG. 6 is an exploded perspective view of FIG. 5.

BEST MODE FOR CARRYING OUT THE INVENTION

The configuration and operation of preferred embodiments of the present invention are described hereafter in detail with reference to the accompanying drawings.

FIG. 3 is a cross-sectional plan view showing the structure of a plane type heat exchanger according to an embodiment of the present invention and FIG. 4 is an exploded perspective view of FIG. 3.

A heat exchanger 100 according to a first embodiment of the present invention includes a plurality of heat exchange pipes 135 that are arranged at regular intervals in parallel with each other, inner plates 140, 141 where both ends of the heat exchange pipes 135 are inserted and fixed, and outer plates 150, 151 that cover the outer surfaces of the inner plates 140, 141 and form spaces inside.

The heat exchange pipe 135 is a plane type having a rectangular cross section that is larger in width of a side, which contacts with combustion gas making laminar flow than height and the side contacting with the combustion gas is flat, such that manufacturing is easy.

Insertion holes 140 a, 141 a are formed through the inner plate 140, 141 and both ends of the heat exchange pipes 135 are inserted in the insertion holes 140 a, 141 a.

The heat exchange pipes 135 are inserted in the insertion holes 140 a, 141 a formed through the inner plate 140, 141 and brazing is applied to the portion where both ends of the heat exchange pipes 135 are inserted in the insertion holes 140 a, 141 a of the inner plate 140, 141, such that sealing is maintained.

In the heat exchanger 100 using laminar-flow combustion gas, the gaps between the heat exchange pipes 135 that are arranged in parallel should be maintained at regular intervals to increase heat transfer efficiency. Further, the laminar flow of the combustion gas should be maintained by forming the gaps within 0.5 to 2.0 mm to achieve effective heat transfer.

The outer plates 150, 151 are attached to the outer surfaces of the inner plates 140, 141, such that empty spaces are formed inside between the inner plates 140, 141 and the outer plates 150, 151.

A heating water inlet 131 is formed at the outer plate 150 and heating water outlet 132 is formed at the other outer plate 151.

Heating water flows along paths indicated by arrows in FIG. 3. Heating water flowing into the heating water inlet 131 flows into the space between the outer plate 150 and the inner plate 140, circulates inside the heat exchange pipes 135 through the insertion holes 140 a formed through the inner plate 140, flows into the space between the other inner plate 141 and the outer plate 151 through the insertion holes 141 a formed through the inner plate 141, and then is discharged outside through the heating water outlet 132.

That is, in the plane heat exchanger 100 according to the first embodiment of the present invention shown in FIGS. 3 and 4, heat transfer is made while the heating water circulates in one direction inside the heat exchange pipes 135.

FIG. 5 is a cross-sectional plan view showing the structure of a plane type heat exchanger according to another embodiment of the present invention FIG. 6 is an exploded perspective view of FIG. 5.

A heat exchanger 200 according to a second embodiment of the present invention has a configuration in which heating water circulates in an S-shape such that the paths alternate inside heat exchange pipes 235.

Further, sub-plates 245, 246 are provided between inner plates 240, 241 and outer plates 250, 251 to make brazing easy. That is, brazing is easily applied to materials that are difficult to braze.

The heat exchanger 200 according to the second embodiment includes a plurality of heat exchange pipes 235 that are arranged at regular intervals in parallel with each other, the inner plates 240, 241 where both ends of the heat exchange pipes 235 are inserted and fixed, the sub-plates 245, 246 that are attached to the inner plates 240, 241 and support the outer plates 250, 251 to form flow channels of heating water, the outer plates 250, 251 that cover the outer surfaces of the sub-plates 245, 246 and are divided into a plurality of sections having spaces inside, and fixing plates 260, 261 that fix the outer plates 250, 251 to the sub-plates 245, 246.

Both ends of the heat exchange pipes 235 are inserted and in insertion holes 240 a, 241 a formed through the inner plates 240, 241 such that the heat exchange pipes 235 are fixed at regular intervals, and the heat exchange pipes 235 are firmly brazed by the sub-plates 245, 246. Flow channel holes 245 a, 246 a of the sub-plates 245, 246 are smaller than the heat exchange pipes 235 and both ends of the heat exchange pipes 235 are in close contact with the sub-plates 245, 246.

The outer plates 250, 251 are substantially bent in a U-shape and cover the outer sides of the flow channel holes 245 a, 246 a formed through the sub-plates 245, 246, and both edges of the outer plates 250, 251 are sealed, such that airtightness of the heating water is kept.

The heating water circulates in the directions indicated by arrows shown in FIG. 5. That is, the heating water flows into a heating water inlet 231, passes through the space covered by the outer plate 250, circulates along the heat exchange pipes 235 through the flow channel hole 245 a formed through the sub-plate 245 and the insertion holes 240 a formed through the inner plate 240, and continues flowing into the space covered by the outer plate 251 through the insertion hole 241 a formed through the other inner plate 241 and the flow channel hole 246 a formed through the sub-plate 246.

Thereafter, the heating water changes the flow direction along the next heat exchange pipe 235 that is communicated with the outer plates 250, 251 and sequentially flows as shown in FIG. 5. As a result, the heating water is discharged outside through a heating water outlet 232, for heating or hot water.

INDUSTRIAL APPLICABILITY

As described above, a plane type heat exchanger according to the present invention has plane type multi-layered heat exchange pipes, which are arranged at regular intervals, such that it is possible to easily manufacture and improve heat exchange efficiency. 

1. A plane type heat exchanger that has heat exchange pipes, through which heating water flows, and makes heat exchange by contacting with laminar-flow combustion gas, the plane type heat exchanger comprising: a plurality of heat exchange pipes that have a rectangular cross section with a larger width of a side, which contacts with the combustion gas, than the height, and are arranged at regular intervals in parallel with each other; inner plates where both ends of the heat exchange pipes are inserted to be fixed at regular intervals; and outer plates that are communicated with the heat exchange pipes through the inner plates and form spaces covering the outer surfaces of the inner plates.
 2. The plane type heat exchanger according to claim 1, wherein insertion holes having sizes close to the cross-sectional area of the heat exchange pipes are formed, at positions corresponding to the heat exchange pipes, through the inner plates and both ends of the heat exchange pipes are inserted in the insertion holes.
 3. The plane type heat exchanger according to claim 1, a sub-plate is provided between the inner plate and the outer plate.
 4. The plane type heat exchanger according to claim 3, wherein flow channel holes having sizes smaller than the cross section of the heat exchange pipes are formed through the sub-plate.
 5. The plane type heat exchanger according to claim 4, wherein both ends of the heat exchange pipes are in close contact with the sub-plates.
 6. The plane type heat exchanger according to claim 3, wherein brazing is applied to between the inner plate and the sub-plate, the heat exchange pipe and the inner plate, and the heat exchange pipe and the sub-plate.
 7. The plane type heat exchanger according to claim 1, wherein brazing is applied to portions where both ends of the heat exchange pipe is inserted in the inner plate.
 8. The plane type heat exchanger according to claim 1, wherein the outer plate is divided into a plurality of sections. 